Abstract: We propose a phase unwrapping approach. With local frequencies estimated by the maximum likelihood (ML) estimator, the unwrapped phase at the central pixel of a local image is obtained by fitting unwrapped phases with an ideal plane assumed. We take a region-growing strategy in which a quality map guides the phase unwrapping from high-quality pixels to low-quality pixels, minimizing the propagation of errors to a maximum degree.

Key words: local frequency estimation, region growing, finite element method, phase unwrapping, interferometric SAR